\begin{tikzpicture}[>=Stealth, scale=0.8,
    every node/.style={fill=white, inner sep=1pt},
]
    \pgfmathsetmacro{\rxa}{-1}
    \pgfmathsetmacro{\rya}{-2.7}
    \pgfmathsetmacro{\rxb}{6}
    \pgfmathsetmacro{\ryb}{3.8}
    \draw [thick] (\rxa, \rya) rectangle (\rxb, \ryb);

    \pgfmathsetmacro{\xa}{0}
    \pgfmathsetmacro{\ya}{0}
    \pgfmathsetmacro{\xb}{2.8}
    \pgfmathsetmacro{\yb}{2.6}
    \pgfmathsetmacro{\xc}{4.8}
    \pgfmathsetmacro{\yc}{-1.5}
    \pgfmathsetmacro{\r}{0.7}

    \draw [thick] (\xa, \ya) node [below right] {$A$} circle (\r);
    \draw [thick] (\xb, \yb) node [below right] {$B$} circle (\r);
    \draw [thick] (\xc, \yc) node [below right] {$C$} circle (\r);

    \filldraw [fill=black] (\xb, \yb) circle (0.05);
    \filldraw [fill=black] (\xc, \yc) circle (0.05);

    \draw [->] (-2, 0) -- (7, 0) node[below=0.2em] {$x$};
    \draw [->] (0, -3.5) -- (0, 4.5) node[left=0.2em] {$y$};
\end{tikzpicture}

